Phonograph reproducer



Patented Apr. 17, 1923.

arr stares ALBERT B. BEEN, OF PHILADELPHIA, PENNSYLVANIA.

PHONOGBAPH REPRODUCERI.

Application filed November 1, 1921. Serial No. 512,112.

To all whom it may concern:

Be it known that I, ALBERT B. REHN, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Phonograph Reproducers, of which the following is a specification.

This invention relates to phonograph reproducers, and it contemplates, first, an improved reproducer constructed so asto interfere as little as possible with the delivery of the sound-waves into the atmosphere and so that at the same time, if the reproducer is pivoted to its support as is usual, it will stand in convenient relation to such support for the facile performance of its pivotal movements; and, second. in such a combination of a sound-box of the class having opposite spaced upright diaphragms and a forked stylus device whose arms are in vibration-transmitting relation to the respective diaphragms that adjustment may be effected to vary the tension of the said arms and hence of the diaphragms. Other objects will appear hereafter.

The drawing shows in all the figures a reproducer embodying my first-named object of invention, the first four views showing the reproducer in one form and the lastthiee views showing it in another form for the carrying out of my second object of invention. I

In said drawing,

Figure l is a side elevation of the firstmentioned form;

Figure 2 is a sectional view on line 2-2, Fig. 1; v

Figure" 3 is a plan of said form;v

Figure 4: is an enlarged fragmentary transverse sectional view in the plane of a certain stud t appearing in Fig. 1;

Figure 5 is aside elevation of the second mentioned form;

Figure 6 is a front elevation, partly in section, of the same; and V Figure 7 is an enlarged fragmentary sectional view of said second-mentioned form.

Referring, first, to Figs. 1 to 4: i

The sound-box here includes two cylindrical sections a b secured together by screws c, the outer faces of the sections being oblique relatively to their inner or contiguous faces. which are in planes at right angles to a the cylindrical-axis of the sound-box, and

the sections are secured together so that their narrowest portions are opposite each other, which makes the sound-box of tapering form when viewed as in Fig. 2. Each section has at its outer face an inward flange cZ.

Rubber annuli e 6, each interiorly and continuously grooved and holding in its groove a diaphragm f, rest against the inward faces of the flanges (Z. They are held thereagainst by suitable'interposed spacing means, being in the present case a spacing ring 9 whose lateral faces converge, being parallel with the outer faces of the sections a b, and the annular rim h of a disk-shaped centrally apertured sound amplifying plate At the top of the sound-box is an elongated sound outlet j whose length approximates the diameter, and whose width the width, of the interior of the sound-box. The top of the sound-box has a horn 7c (in the present example formed independently of the sound-box but attached thereto by screws is) which tapers outwardly and projects substantially tangentially from the cylindrical wall of the sound-box in covering relation to the outlet; the free or smaller end of this'horn terminates in a cylindrical hearing A whose axis is parallel to the axis of the cylindrical wall of the sound-box and which is adapted to be ournaled on the stub Z of a support on being held againsta shoulder Z on the stub by a screw it screwed into the latter, said stub forming the tubular turned-off end of a well known form of horn which support m constitutes, the same being mounted. as by being pivoted. to swing on a vertical axis, on the phonograph machine. The joint at 7o-Z is such that the sound box is held always in a vertical position, with its outlet 7' up.

One of the sections a 7) of the sound-box. as a, has a conical bearing recess 19. This is arranged in the central vertical plane of the sound-box, and in order to avoid its coincidence with the plane of contact of the sections a and 7) section a may have an offset luv: 0; (Fig. 4) in which the recess is formed. A plate spring 1. twisted around its longitudinal axis to give it a certain amount of stiffness'while leaving it somewhat flexible and having its end portions bent off in opposite directions, is secured to the under side of the sound-box at one of said ends by means of a screw 1 and depends from the sound-box. The other end has an upstanding bearing point or pivot a.

Journaled in the bearing recess p and on the pivot s is a stud or post If whose upper end is pointed and whose lower end is recessed to match the recess 39 and pivot s, respectively, said stud having a knurled head 8. The stylus device is a fork-shaped member whose shank u is formed tubular at its lower end to receive the point or needle 0, held therein by the set-screw w, and has an arm as projecting toward the spring 9, having stud t penetrating and tapped into it-(the stud and shank beingapproximately parallel), 3/ being a lock-nut on the stud which, after the stylus device has been adjusted by turning the stud in the same, may be jammed against the arm a". The fork arms a of the stylus device project upwardly from the shank and at their upper ends are bent inwardly and formed with more or less broad-faced pads or seats 2 which bear against the diaphragms i The sound-box, by having a soundbutht j at the top, formed as stated, and by having in covering relation to this outlet the tapering horn projecting tangentially from the cylindrical wall of the sound-box, presents these advantages: Sound-waves set up in the sound-box find their way into the horn m with the least possible interference by, and consequent production of vibration in, the structure thereof, so that not only is the volume of the delivered sound increased a but metallic sound effects are eliminated and the sound is a faithful reproduction of that which the record is designed to ive off. The structure including the soundox and horn j, by having the latter projecting from the top of'the former in tangential relation thereto and its most weighted portion (the sound-box) in substantially pendent rela- "tion to the remainder (the horn) in the normal or working position of said structure, permits the latter to be so grasped and held by the operator in moving it from or toward said position on its bearing 7o"-Z that there is greater assurance than in ordinary structures of this class that the same will not slipand fall against and possibly injure the record.

7 The support formed by the parts 7-t is capable of yielding in various directions on the bearing point p,- in fact, it has universal movability on such point, being however normally urged to the position indicated in Figs. 1 and 2 by its spring portion 9. Thus while said spring portion allows it to yield laterally when the reproducer is used in connection with a lateral-cut record,

said spring portion, acting as a cushion, also absorbs shocks that would be incident to up and down deviations in the record, as malformations or irregularities produced by marring, so that the production of harsh, grating sounds due to such deviations is reduced.

Moreover, it will be noted that the stylus device maybe adjusted (by turningthreaded stud in the arm a; of the stylus device) transversely ofthe sound-box and that the result thereof will be to alter the tension of both the fork arms of said device and the diaphragms, and consequently'the resulting soundefiect, due to the convergent relation of the latter. I

In phonograph reproduction of sound the low-pitched tones are usually delivered in insufficient volume, so that when low-pitch and high-pitch sounds are reproduced simul taneously or nearly simultaneously the lowpitched are sometimes overwhelmed by the high-pitched sounds. I accordingly prefer that one of the diaphragms be tense than the other, so that it will be better adapted than the other for transmitting low-pitch sounds, and to preferentially amplify the sounds generated at this diaphragm I place the amplifier 21 in cooperative relation thereto-that is, between the sameand the sound-outlet.

To limit the swinging-back movement of the structure including the sound-box and horn 7c on the bearing 7a'(Z a lug 3 on the horn m is adapted to be impinged by a. shoulder t formed on the bearing 76".

Referring, now, to Figures 5 to 7. In this case the sound-box includes a cylindrical section 6 having aninternal flange 7 at one side, and an interior screw thread 8 at the other, both sides of the section Gbeing in this case at right angles to its cylindrical axis. A threaded annulus 9 is screwed into the section 6 in engagement with its threading 8. Each diaphragm 10 is set in the interior groove of a rubber annulus 11. There is a centrally apertured disk-shaped amplifying plate 12 adapted to abut a shoulder 13 in the section 7 at the base of the screw threading 8. One of the diaphragm-carrying annuli 11 is arranged to bear against the flange 7, being held thereagainst by a spacing ring 14: interposed between said annulus 11 and the plate 12, and the other annular 11 is held between the-plate 12 and the annulus 9.- To vary the widthof the sound-box from diaphragm to diaphragm in the present case diaphragm-carrying annuli 7 having the diaphragmsset different distances from the lateral faces of the an nuli, maybe substituted for those shown in the drawing. The section 6 has a top sound outlet 6 in all respects the same as the outlet j already described and projecting from horn m in the manner already described and shown in Fig. 3. t

- At its under side the section 6 has two lee spaced lugs 17 arranged in the same plane at right angles to the cylindrical axis of said section. One of these forms a hearing at 17' and in the other is set bearing screw 18 having a lock-nut 18. In the bearings 17 and 18 are journaled the pointed trunnions 19 of the shank 20 of the stylus device, said shank having its lower end tubular and receiving the point or needle 21 held therein by the set-screw 22. The stylus device in this case is also forked. One fork arm 23 is an integral part of the shank. The other fork arm 24 is pivoted in a lug 25 extending from the shank and has a projection 26 in which is tapped a set-screw 27 to bear against the shank. In this case the adjustment of the tension of the arms 23 and 24 of the stylus device and consequently of the diaphragms is eitected by turning the screw 27 so that the arms will exert more or less pressure on the diaphragms. The ends of said arms terminate in pads 28 which bear against the diaphragms and are held thereto by screws 29 penetrating the diaphragms from the inside and tapped into said pads.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is Y 1. In combination, a sound-boX-including structure having opposite convergently arranged sound-box walls, one of which is a. diaphragm, and a forked stylus device carried by the sound-box and having its fork arms respectively bearing against said walls,

said stylus device being adjustable in said structure relatively to said walls toward and from the direction in which they converge.

2. In combination, a. sound-box having a ibratory sound-wave producing member, a

stud having one end bearing against the sound-box and shittable on said end to positions of varying angularity 'with respect to the sound-box, resilient means normally holding the stud in one of said positions, and a stylus-device having contact with said member and rigidly attached to the stud.

3. In combination, a sound-box having a vibratory sound-wave producing member, a stud having one end bearing against the sound-box and shiftable on said end to positions of varying angularity with respect to the sound-box, a spring attached to the sound-box and having holding engagement with the other end of the stud, and a stylus Clevicahaving contact with said member and rigidly attached to the stud.

4. In combination, asound-box-including structure having a sound-wave-producing member, a"rotary threaded stud journaled at one end in the sound-box part of said structure and at the other end in another part of said structure, and a stylus device bearing against said member and penetrated by and having threaded connection with the stud.

In testimony whereof I afiix my signature.

ALB ERT B. REHN. 

